The present invention is directed to a fire-fighting monitor and, more specifically, to a portable fire-fighting monitor that incorporates a safety system that controls the rotation of the monitor's nozzle to keep the monitor from overturning or moving due to the reaction force generated by the flow of fluid through the monitor.
Fire-fighting monitors include an inlet, which is connected to a hose or pipe, and a discharge outlet to which a nozzle or stream shaper is mounted. Monitors typically deliver a large quantity of fluid (typically water or foam) and, as a result, generate a reaction force that increases with an increase in the fluid flow and/or pressure. This reaction force extends in the opposite direction from the flow of the fluid and, therefore, can act on the monitor to create a moment about the base of the monitor, depending on the direction of the nozzle. For portable monitors, this reaction force can be destabilizing. When the nozzle is oriented so that the reaction force extends within the footprint (i.e. within the perimeter of the outer circumference of the monitor, which is defined by the ground contact points of the monitor's supports) of the monitor, there will be no destabilizing moment; though a translational force may be generated. However, when the reaction force does not pass through the footprint of a portable monitor, portable monitors are susceptible to overturning and/or sliding. Furthermore, the weight of the nozzle or stream shaper has a tendency to urge the nozzle or stream shaper to pivot downward, where the reaction force will have a greater tendency to tip or slide a portable monitor. While control over the flow of fluid through the monitor can reduce the reaction force to safe levels, conventionally portable monitors do not have manual shut-off valves. Instead, the flow of fluid through the monitor is limited through a valve at the fire truck or at the fire hydrant.
Various modifications have been proposed. However, many of these modifications increase the weight of the monitor and, further, complicate the assembly of the monitor. To facilitate the control of the reaction force, some monitors have incorporated one-way brakes. However, there is a need to provide a simplified assembly that can achieve greater control over the monitor, but without the attendant costs and complicated construction of some the prior art monitors.